Microwave Annealing Effect for Highly Reliable Biosensor: Dual-Gate Ion-Sensitive Field-Effect Transistor Using Amorphous InGaZnO Thin-Film Transistor

We used a microwave annealing process to fabricate a highly reliable biosensor using amorphous-InGaZnO (a-IGZO) thin-film transistors (TFTs), which usually experience threshold voltage instability. Compared with furnace-annealed a-IGZO TFTs, the microwave-annealed devices showed superior threshold voltage stability and performance, including a high field-effect mobility of 9.51 cm²/V·s, a low threshold voltage of 0.99 V, a good subthreshold slope of 135 mV/dec, and an outstanding on/off current ratio of 1.18 × 10⁸. In conclusion, by using the microwave-annealed a-IGZO TFT as the transducer in an extended-gate ion-sensitive field-effect transistor biosensor, we developed a high-performance biosensor with excellent sensing properties in terms of pH sensitivity, reliability, and chemical stability.